Question

@iambatman So what with a(x-h)^2+k? :)

Answer 1

Well it's easier to work with vertex form, when a>0, the y coordinate of the vertex represents a minimum, and if a <0, it represents a maximum.

Vertex \[(\frac{ -b }{ 2a },f(\frac{ -b }{ 2a }))\]

Does that make sense?

Answer 2

this drawing should make it more clear (sorry it should be symmetric but I have an injured finger so I can't really draw so well right now XD)